cracked_doc wrote:A friend of mine told me that there have been such a news...have you ever heard of a thing like this? and is it possible?

If u mean on experiments with 2 eggs It wouldn't be possible to get viable embryo because DNA metilation would be different from the one of sperm cell...as I remember. It's not possible... but yeah I heard they are experimenting with stem cells

Zami87

Every man is a star whose light can make shadows dance differently and change our view of landscape permanently***

Well the question was actually if sperm cells could be made, not male gametes. The Y-chromosome has no bearing on this, otherwise clearly males would produce eggs as well as sperm depending on which sex chromosome made it into the nucleus.

Under normal conditions, clearly no women cannot make sperm *shudders*. But I suppose theoretically if one were to take an immature egg cell and expose it to certain chemical cues and then nurture it...a sperm cell could be made.

Yes, much like the sperm-from-stem cell experiment that Darby speaks of.

The point I was making was that spermatogenesis requires at least a couple of genes carried on the Y chromosome. Which way the sex chromosomes go at that point isn't an issue (and sperm cells are the same thing as male gametes, at least whenever I've heard them discussed).

Males can make egg cells, when you get hermaphroditic mosaicism (embryonic abdominal cells divide improperly, producing a cell line without a Y chromosome).

And the experiments I referred to weren't making sperm, they were using sperm stem cells (spermatogonia, I assume, but I don't remember it being specified) to produce other kinds of cells.

the sex is determines from SRY region which is a gene that is situated on the short branch of Y chromosome. this determine that the embryo will be male. Thus being female the paternal chromosome is X and maternal is X too so XX gives female embryo. On both cases they produce a chain reactions which activate different hormones female or male hormones. The Male hormone is testosterone and female is progesterone. Those hormones have the secondary effects on individual body and this is related also with sexual hormones and organs. So a woman can not produce sperm becasue she needs to have testicules and the sperm is produced on special cells of testicules and they need to be activated by testosterone (male hormon).
So in a few words there is no any chance that a woman CAN NOT produce sperm.
there are known different syndromes like Turnes Syndrome when they have XXY, or Chlainepher Syndrome XXXY, and so on. But they are sterile.

I think I see what you're saying - in your definition, a sperm carrying a Y chromosome is a male gamete. The thing is, that's a fairly odd definition.

As mentioned above, most of us are used to the terminology of sperm being the most common form of gamete produced by males (and that applies to plants, too, dioecious or monoecious), or male gametes, with egg cells / ova being female gametes. The gametes define the genders, after all.

And, by your definition, many organisms would have no male gametes, since determinism by chromosome is the minority approach to gender.